Clamp mechanism for rotary car dumper

ABSTRACT

A railroad car is secured for dumping in a rotary car dumping cradle by gravity lowered clamp beams which engage the top of the car and are locked in place by a gravity actuated, infinitely variable locking mechanism that grasps tension members connected to the side of the car dumper.

United States Patent [191 Ouska 1 [451 March 6, 1973 1 CLAMP MECHANISMFOR ROTARY CAR BUMPER [75] Inventor: Ralph C. Ouska, Hinsdale, Ill.

[73] Assignee: FMC Corporation, San Jose, Calif.

[22] Filed: April 21, 1971 [21] Appl. No.: 135,960

[52] U.S. Cl ..214/55 [51] Int. Cl ..B65g 67/54 [58] Field of Search..2l4/55, 56

[56] References Cited UNITED STATES PATETQTS 2,634,006 4/1953 Cdii'r'ii...214/55 1,606,453 11/1926 Simpson ..2l4/55 Primary ExaminerR0bert G.Sheridan Attorney-F. W. Anderson and C. E. Tripp [5 7] ABSTRACT Arailroad car is secured for dumping in a rotary car dumping cradle by.gravity lowered clamp beams which engage the top of the car and arelocked in place by a gravity actuated, infinitely variable lockingmechanism that grasps tension members connected to the side of the cardumper.

4 Claims, 21 Drawing Figures go 32. 2 7. 2. 9e 9 A 8 PATENTEDHAR 61mRALPH c. o'usKA INVENTOR SHEET [MM 10 F'II3 2 ATTORNEYS PATENTEDHAR' fi3,719,292

SHEET UBDF 10 PATENTEDHAR 6 ms saw on HF 10 TIB '7 ws w T'I[3 ElPATENTEU m 5 SHEET O7DF 10 PAIENIED 5W5 SHEET UBBF 10 PATENTEU 5 I973SHEET 10 HF 10 BACKGROUND OFTI'IE INVENTION The present inventionrelates to clamping devices for a rotary railroad car dumper. Moreparticularly the present invention relates to mechanisms forautomatically positioning and locking a railroad car clamping device ina rotary car dumper.

Modern systems for bulk handling of various material such as coal, coke,wood chips or the like generally make use of a car dumper machine forrapidly unloading railroad cars individually, in groups or by the train.Railroad siding tracks pass through the machine to enable a single caror group of cars to be stopped and held inside a cradle that can berotated to turn the railroad car over and empty its contents into ahopper below.

. Various clamp mechanisms have been employed to hold the car fromfalling away from the track and sup porting table while it is beingturned over. Many combinations of cable, sheaves, racks, drums, chains,band brakes, hooks, ratchets and pawls have been employed to lift andhold clamping beams and hooks in contact with the railroad car body.Gravity, electric motors, hydraulic cylinders and the motion of the cardumper have been used to provide power to operate thesev mechanisms.

One device presently in use, which is described in U.S. Pat. No.l,606,453 to Simpson, includes a car dumper having individually actuatedhook members that slide downwardly into engagement with the sides of arailroad car under the influence of a sheave and rope arrangement. Oncethe car is engaged,-the hooks are individually locked by lockingmechanisms comprised of alternate friction plates and clamp bars thatare forced into frictional locking engagement during dumper rotationbythe coaction of a series of wedges and rollers actuated by acounterweight. Another mechanism for clamping a railroad car in a rotarycar dumper, as described in U.S. Pat. No. 1,609,420 to Norris, utilizesgravity lowered clamping hooks which are locked into engagement with arailroad car by a locking mechanism having jaws forced together bytoggle-linkage to grasp a vertical bar. The toggle-linkage of thisdevice is actuated by a cable and sheave arrangement.

In all cases, positive operation of the locking clamps is an object ofhigh priority because of the possible disastrous results if theclampsare not firmly locked as the loaded cars are inverted. Thisproblem is particularly acute in some environments. For example, thecontents of coal or ore cars operating in extremely cold climatessometimes freeze solid to the body of the car and will not dump wheninverted. This places the gross weight of the loaded car, a weight ofperhaps 200 to 300 tons directly onto the locking clamps. Thus, whilesafe locking clamps are an absolute requirement for all rotary cardumpers, the attainment of a safe locking clamp system without directlyor indirectly applied power actuation has heretofore'been limited to cardumpers which operate under conditions more favorable than extremelycold climate use where counterweighted locking clamps might be prone tomalfunction.

The car clamp systems now in use have either to all r or many of thefollowing disadvantages. They are complex mechanisms, subject tojamming, which are difficult and costly to build and install and whichrequire frequent maintenance and adjustment. Some require auxiliarypower, while some require duplicate or back up components to assuresafety under severe load conditions.

Accordingly, a general object of the present invention is to providelocking clamps which are automatically operable and safe in all,including sub-zero, temperatures.

A further object of the invention is to provide a clamping arrangementwith less complex structural and mechanical components, with less wearand less need for adjustments and with no requirements for auxiliarypower.

Another object of the invention is to provide a positive means oflowering a clamping mechanism into engagement with a railroad car.

A further object of the invention is to provide a means within arailroad car clamping mechanism for relief of forces created by thecompression in railroad car truck springs.

SUMMARY OF THE INVENTION In the present invention, a car clamp isprovided which is positioned and locked only by gravitational forces.These forces are exerted during rotation of the cradle without relianceon auxiliary power or force transmitting cable and with minimum linkage.In the preferred form of the invention, beam clamps initially held inelevated position by a stationary post, are lowered along guides by theaction of gravity during the dumping cycle to hold a railroad car inplace in a rotary car dumper cradle. As the dumper is rotated, the beamclamps drop into contact with the top of the car, and once in place atopthe car, the clamps are locked in that position. The locking mechanismutilized to lock the clamps in place is activated by the action ofgravity, as are the clamps, so that no power source, other than thatused to rotate the cradle, is necessary. An actuating weight mounted atthe end of a lever, which changes its moment direction as the dumper isrotated, supplies the force necessary to actuate the lock. A clamp barassembly of the lock mechanism is defined by a series of spaced platesinterspersed between a series of parallel spaced metal strips that areconnected to the side of the cradle and are slidable relative to thespaced plates when the lock mechanism is unlocked. As the cradle isrotated beyond 35 of rotation toward the dumping position the weightmoment shifts, causing a series of toggle links, which areinterconnected with the actuating weight lever, to extend. The extensionof the toggle links forces the plates of the lock mechanism into verytight locking contact with the strips of the clamp bar assembly to holdthe beam clamps in position on top of the car during the dumping cycle.Thus, the clamp is always lowered and locked by gravity forces, andthere are no cables to break or jam.

Further features of this invention incorporate positive lowering of thebeam clamps and relief of truck spring compression forces.

DESCRIPTION OF THE DRAWINGS present invention with portions being brokenaway.

FIG. 2 is a fragmentary diagrammatic perspective illustrating one of thetwo beam clamps shown in FIG. 1.

FIG. 3 is'a diagrammatic end elevation of the apparatus shown in FIG. 1with the near circular cradle end removed.

FIG. 4 is a diagrammatic perspective of the locking mechanism of thepresent invention with parts removed.

. FIG. 5 is a fragmentary horizontal section taken along line 5-5 ofFIG. 2 showing the upper guide rollers of the clamp hook assembly.

' FIG. 6 is a fragmentary horizontal section taken along line 6-6 ofFIG. 2 as viewed from below showing the guide rollers on one side of theclamp assembly.

FIG. 7 is a fragmentary side elevation of the locking mechanism of thepresent invention with portions being broken away.

FIG. 8 is a horizontal section of the locking mechanism taken along line8--8 of FIG. 7.

FIG. 9 is a vertical section of the locking mechanism taken along line9-9 of FIG. 7.

FIGS. 10, ll, 12 and 13 are diagrammatic end elevations of the apparatusshown in FIG. 1, in four operational positions.

FIGS. 14 and 15 are fragmentary diagrammatic end elevation of a secondembodiment showing the positive clamp lowering mechanism in twooperational positions.

FIG. 16 is a diagrammatic perspective of the clamping mechanismincorporating positive clamp lowering with parts removed.

FIG. 17 is a fragmentary plan view of the clamping mechanism of FIG. 16.

FIG. 18 is an end elevation of the clamp mechanism of a third embodimentwith parts broken away.

FIG. 19 is a plan view of the clamp mechanism of FIG. 18.

FIG. 20 is an enlarged vertical section taken along line 20-20 of FIG.18.

FIG. 21 is a diagrammatic perspective with parts removed of the clampmechanism incorporating the truck spring relief apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 3,there is shown the general organization of the preferred form of theinvention in which a railroad car R is supported within a rotatablecradle structure of a rotary car dumper 32. The opentop car R is heldfor rotation within the cradle structure 30 by two clamp mechanisms 34.The cradle structure 30 is rotated by a drive system 36 into position todump the contents of the railroad car down a chute 31.

More specifically, the cradle 30 of the rotary car dumper 32 is anessentially U-shaped structure. The U- shaped cradle 30 is constructedof longitudinal horizontal beams 38,40 and 42 that are rigidly securedbetween a pair of circular ends 44 and 46, vertical beams 48 and 48a anddiagonal members 50 and 50a secured between the horizontal members togive structural rigidity to the cradle structure, and cross beams 52that extend transversely between the lower horizontal members 42. Aplatform 54 that extends the length of the cradle structure and throughopenings 58 in the circular ends is supported on parallel support beams56 that overlie the transverse beams 52. The ends of the platform 54 arecontiguous to walls 60 of a pit 62 in which the car dumper is disposed.Rails 64 overlie the platform 54 and support the car R for movement intoand out of the cradle through the openings 58. Therails 64 are in linearalignment with rails 66 on the surface inlet and discharge sides of thepit.

Cradle 30 is supported for rotation 8c0205 on four rollers 68 which arerotatively supported on support members 70 anchored in the base of thepit. Tracks 71 extend partially about the periphery of each of thecircular ends 44 and 46 and mate with the rollers 68 that support thecradle in rotation.

Power for rotating the cradle 30 is supplied by a reversible electricmotor-gear reducer unit M' (FIG. 1) which has power shafts 72 each ofwhich terminates near one of the cradle ends 44 and 46. A pinion gear(not shown) at the end of each shaft 72 drives a large ring gear (notshown) which is part of a cable winch 74. A cable 76 of each winch isspirally wound on a drum 78 of the winch 74 and has ends secured byanchors 79 to the respective cradle ends 44 and 46 for rotation of thecradle 30 to the dumping position, and for the return of the cradle fromthe dumping position, as the motor unit M is energized.

The clamping mechanisms 34 are supported within the cradle 30 by twovertical support members or trusses 82 which are secured to thehorizontal beams 38, 40 and 42 near each of the circular ends 44 and 46.Each of the support members 82 is constructed of beams 82a securedtogether in a spaced parallel orientation to present a slot 84 (FIG. 8)therebetween.

Each of the clamping mechanisms orcar securing members 34 is identicalin structure to the other and functions independently of the other. Eachclamping mechanism includes a carriage 88 having an upright member 90(FIG. 2) mounted for endwise movement on a pair of rails 86, an uppertransverse member 92 rigidly secured to the upright member 90 andextending inwardly of the cradle, a lower transverse member or lift beam94 rigidly attached to the upright member 90 and extending outwardlyfrom the cradle through the slot 84 in the vertical support member 82,and a clamp beam 96 suspended from the upper transverse member, aclamping element 98 (FIG. 7) secured at either end to the truss 82 andextending vertically in the slot 84of vertical support member 82, and avertically extending post or lift member 100 secured to the surfaceadjacent the cradle structure.

The upright member 90 (FIGS. 2, 6 and 7) is an elongated rectangularstructure that engages the rails 86. A combination of rollers andbearing bars attached to the upright member 90 contact the rails 86 andguide movement of the upright member 90 relative to the rails 86. Therollers are positioned for maximum contact with the rails 86 as thecradle overturns. At thetop of the upright member 90 one pair of rollers102 is positioned (FIGS. 2 and 5) such that they contact the inner edgesof rails 86. A second pair of rollers 104, attached near the top of theupright member 90, is positioned to engage the rear surfaces 86a of therails. A pair of bearing bars 106 secured to the upright member abut theopposite or front faces 86b of the rails 86 and provide a secondarycontact surface as the upright member moves relative to the rails 86.

A pair of rollers 108 (only one being shown in FIGS. 2 and 6) secured tothe lower end of the upright member 90 engage the front faces 86a of therails 86. Another pair of rollers 110 (FIGS. 2 and 6), mounted onbrackets 112 at the lower end of the upright member 90, follow the outeredges of rails 86. Bearing bars or shoes 114, (FIG. 6) which are securedto the lower portion of the upright member 90, contact the back faces86a of rails 86.

The upper transverse arm 92 is constructed of spaced parallel plates 92a(FIG. 2) which are rigidly secured at one end to the upright member 90.At the other end of the transverse arm 92, clamp beam 96 is disposed ina slot between the plates 92a on a pivot pin 116 that extends throughthe plates 92a. Pivot pin 116 is retained at the ends by collars 116asecured to the plates 92a and to the pin 116. The clamp beam 96 which ispivoted at its center on pin 116 includes a horizontal center portion96a and arms 96b extending diagonally downwardly from the horizontalportion. Clamp pads 118 and 120 are secured to arms 96b for engagementwith the sides of an open-top car R. Vertically disposed channel members122 (FIG. 1), which are secured to the cradle opposite the verticalsupport members 82, serve to guide the outer contact pads 120 as theclamp beam 96 moves up or down relative to the cradle 30.

The lower transverse arm 94 includes a pair of beams 94a (FIGS 2 and 8)rigidly secured in spaced, parallel relationship. A roller or cam 124 issecured for rotation on a shaft 126 between the outer ends of the beams94a. The roller 124 contacts an inclined upper surface of the verticalpost 100 when the cradle is in the upright position.

A locking mechanism 128 that engages the clamping element 98 is securedbetween a pair of clamp brackets 134 (FIG. 9) that overlie the beams94a. The clamp brackets 134 are rigidly secured to the upper surfaces ofthe beams 94a. Hold down brackets 135 are secured between the clampbrackets 134 and the upright member 90 to add structural rigidity.

Referring to FIGS. 2, 3, 4, 7, 8 and 9 the locking mechanism or grippingmember 128 is illustrated in its preferred form. In general the lockingmechanism consists of interconnected linkage 129 which is actuatedduring cradle rotation by the change of position of act uating weight130 to force a series of spaced pressure plates 132 into frictionallocking engagement with a series of elongated strips 98a of the clampingelement bar assembly 98.

More specifically, locking mechanism 128 which is contained within theclamp brackets 134, includes the series of spaced pressure plates orsecond contact members 132 that are interspersed between elongatedstrips or first contact members 98a of the clamp bar assembly 98 asillustrated by FIGS. 4 and 7. The elongated strips 98a are permanentlyspaced at the upper and lower points of connection by spacers 136 (FIG.3) which are placed between alternate strips 98a on connection shafts137. The pressure plates 132, which are slidable relative to the strips98a when the locking mechanism 128 is unlocked, are held and restrainedfrom movement relative to the lock mechanism by the clamp brackets 134(FIG. 9). A spacer or pressure block 138, (FIG. 4), which is arectangular block bolted between clamp brackets 134, maintains thespacing of the clamp brackets 134 and provides a fixed abutment againstwhich the pressure plates 132 and strips 98a are forced during clamplocking.

The toggle linkage 129 (FIGS 4 and 7), which is actuated to force thepressure plates 132 and strips 98a into locking engagement, includes apivot block 140 that is pivotally anchored on shaft 142 to clampbrackets 134. Shaft 142 is retained at its ends by keys 142b that aresecured to the clamp brackets 134. Four fingers 140a of the pivot block140 extend to the left (FIGS 4 and 8) and pivotally interdigitate with apair of toggle links 144 and lever link 146 which are on a common shaft148. Shaft 148 is retained at its ends by the machined inner surfaces ofthe clamp brackets 134. A stop member 150 of shock cushioning materiallimits the upward travel of the toggle linkage when the lock mechanismis in the released position of FIG. 7.

The left ends (FIGS. 4, 7 and 8) of the two links 144 extend intoparallel slots 1520 in pressure block 152. The pressure block 152 is arectangular metal block having a machined exterior and having anindentation l52b formed in one face to receive a pressure plate 154 thatis bolted to the pressure block 152. The ends of links 144 which extendinto slots 152a are rigidly secured to a shaft 156 that extends throughthe pressure block 152 and is bushed for rotation therein. Pressureblock 152 is retained by the machined inner surfaces of clamp brackets134 which provide a bearing surface for sliding movement of the pressureblock 152. The ends of shaft 156 are also retained by the inner surfacesof clamp brackets 134.

The lower end of link 146 (FIGS. 4 and 7) is pivotally connected to anactuating lever 158 to which the actuating weight or element 130 isattached. Lever 158, which is constructed of spaced parallel plates 158a(FIG. 4), is pivoted on a shaft 160 that is anchored to lift beam 94 bymeans of keys 160a (FIG. 2). Link 146 is disposed for movement in theslot between the parallel plates 158a and is pivoted on shaft 162 whichis fixed at its ends to plates 158a.

Having thus described the structure of the preferred embodiment of theinvention, its operation can now be explained. When the dumper 32 is inits initial upright position (FIG. 10) with the railroad car R upright,the clamp beam 96 is held up clear of the railroad car. The roller 124at the end of beam 94 is in contact with the inclined upper surface ofthe lift post 100 when the dumper is in this initial position and theclamp locking mechanism 128 is unlocked. Once the railroad car R ispositioned properly inside the dumper cradle 30 the dumper motor M isenergized causing the cradle to rotate in a counterclockwise directionabout a longitudinal rotational axis L towards the dumping position. Asrotation proceeds the carriage 88 holding the clamp beam 96, which isabove and clear of the car (FIG. 10), begins to drop by its own weightdue to the force of gravity. The clamping mechanism 34 continues to dropuniformly with the roller 124 in contact with lift post 100 until theclamp beam 96 contacts the top edges of the car sides, whereupon clamplowering stops. Rotation continues and the roller 124 loses contact withthe lift post 100. At about 35 cradle rotation (FIG. 11) the center ofgravity of the clamp lock actuating weight 130 passes directly over thepivot point of the actuating 11) 158 with a consequent change in themoment direction of the weight 130 from a clockwise to acounterclockwise direction. As the moment direction of weight 130changes, tension is placed on the lever link 146. The lever link 146 inturn transfers the actuating weight moment to shaft 148 extending tobring the fingers 140a of pivot block 140 and the toggle links 144 to amore linear orientation. This causes the extended toggle links 144 toforce pressure bracket 152 to the left (FIGS. 4 and 7), transmittingpressure to the pressure plates 132, the clamp bar assembly 98 and thepressure block 138. The pressure plates 132 and the strips or bars 98aof the clamp bar assembly 98 are thus forced into a very tightfrictional engagement which stops the sliding motion of the pressureplates 132 relative to the clamp bar assembly 98a and locks the clampbeam 96 against the top edge of the car R.

As the dumper continues to rotate the actuating weight 130 moment keepsthe lock tightly engaged. Material in the car begins to fall out (FIG.12) as the car overturns turns and the dumping process is usuallycompleted by the time the dumper has rotated to the 160 position. Thematerial falling from the car drops into chutes 31 below the cradlewhich conduct the material to below ground conveyors. After all materialhas been dumped, or when 180 rotation (FIG. 13) is reached, the dumpermotor M is reversed. The car springs which were originally compressed bythe load of the material on the car are now held in compression by theclamps 96 which are locked in place. As the 35 point is approached onthe return cycle, the actuating weight moment diminishes, reducing theclamp locking pressure to the point at which the pressure plates 132will again slip in relation to the bars 98a of the clamp bar assembly 98and gradually release the compression of the railroad car springs. Below35 of rotation, the clamp lock 128 is fully released as the roller 124again contacts the upper face of the lift post 100. With roller 124 incontact with post 100, as the cradle rotates to the starting position,the carriage 88 is urged upwardly relative to support member 82, and theclamp beam 96, which is swung from the carriage 88, is lifted out ofcontact with car R. As the upright position is again reached, rotationand upward lifting of the clamp mechanism 80 stops and the railroad carRis ready to be moved out of the dumper 32. If the dumper 32 is to berotated without a car R in place, all operations are the same exceptthat the clamp 96 travels to a stop at a minimum car height and the liftroller 124 moves off of the lift post 100 at about 35 rotation of thecradle.

A further embodiment of the present invention (FIGS. 14, l5, l6 and 17)incorporates a positive clamp lowering mechanism 170 into a clampmechanism 172 equivalent to that described previous'ly. The positiveclamp lowering mechanism is utilized to positively lower the clampingmechanism in case it should jam. The clamping mechanism 172 of thisembodiment includes a carriage 174 having an upright member 176 mountedin a manner identical to that of the previous embodiment, an uppertransverse member 178 from which a clamp beam 180 is suspended extendinginwardly of the cradle from the upright member, a lift beam 182 and alock mechanism identical to that described previously, and the positiveclamp lowering mechanism 170.

The clamp beam 180 of this embodiment (FIG. 16) is pivotally swung on apivot pin 184 between parallel arms 178a of transverse member 178. Thepin 184, which is rigidly secured to the clamp beam, is disposed forvertical travel relative to arms 178a in slots 178b. The pin 184 alsoextends through two parallel spaced arms 186a of lock lever 186. Thespaced arms 186a are pivoted at their left ends (FIG. 14) to thetransverse member 178 on pins 188. A depending curved member 186b oflock lever 186 is secured between the right ends (FIG. 14) of arms 1860.

Another lever, lock arm or hook 190, (FIGS. 14 and 15), is pivotallymounted on a common shaft 192 with a roller 194 at the end of lift beam182. A U-shaped slot 1900 is formed near the lower end of lock arm 190for engagement with a horizontal pin or lock stud 196 that extends fromlift post 198. A flexible cable 200 attached to the lower end of thecurved member 186b of lock lever 186 extends through the central portionof upright member 176 and along lift beam 182 to lock arm 190 to whichthe cable is pivotally connected. A vertically depending rod 202 is alsoconnected to the lower end of member l86b and extends downwardly throughupright member176 and beyond the lower end of the upright member 176.

In operation a railroad car R is moved into position within the rotarycar dumper. The dumper motor is energized and the dumper begins torotate in a counterclockwise direction (FIGS. 14 and 15). At the startof rotation, pivot pin 184 is at the bottom of the slot 178b in which itis disposed and lock lever 186 is in the position of FIG. 14. At thispoint the lock arm 190 is in locked engagement with the pin. 196 (FIG.14) extending from lift post 198.

As rotation proceeds, clamp beam 180, which is above and clear of car R,is lowered as the carriage 174, to which the clamp beam 180 isconnected, lowers on its guides under the force of gravity. However, ifthe clamp mechanism hangs up and doesnt lower properly, lock arm 190,which is in engagement with pin 196, will prevent the roller 194 fromleaving contact with the lift post 198 and the clamp mechanism will bepositively lowered. Clamp lowering, with lock arm 190 in engagement withpin 196, continues until the clamp beam 180 contacts the top edge of thecar sides and stops. The upright member 176 from which transverse arm178 extends continues to drop as pivot pin 184, which is rigidlyattached to both the clamp beam 180 and lock lever 186, moves upwardlyin the slots 178b in transverse member 178. Lock lever 186 is thuspivoted upwardly or in a counterclockwise direction (FIGS. 14 and 15)about pins 188. The motion of lever 186 is transmitted through cable 200to the lock arm or hook 190 which is pulled by the cable in acounterclockwise direction (FIGS. 14 and 15) about shaft 192 and out ofengagement with pin 196. When pivot pin 184 reaches the top of slots178b, the upright member 176 stops its downward movement and the nowfreed roller 194 leaves contact with lift post 198. As rotationcontinues the locking mechanism locks the clamp beam in contact with thetop of the rail car R exactly as described in the previous embodimentand the car is rotated to the dump position.

After the contents of the rail car have been dumped and the car dumperis on the return phase of the dump cycle, the locking mechanism 170disengages as the car reaches a point that is 35 from the uprightposition, as explained in the previous embodiment. Roller 194 againcontacts lift post 198 as rotation continues and the clamping mechanism172 is urged upwardlyQf The clamp beam 180 remains in contact with thetop of car R until pivot pin 184 reaches the bottom of slots 178b in thetransverse member 178. As pin 184 travels downwardly in the slots 178b,lock lever 186 retraces its original path and rotates clockwise to theposition of FIG. 14. Cable 200 imparts a clockwise motion (FIGS. 14 and15) also to lock arm 190 which is rotated again into locking engagementwith pin 196.

If a car dumper, incorporating the positive clamp lowering mechanism, isrotated without a railroad car in place, the lock arm 190 will stilldisengage from lock stud 196 even through the clamp beam doesnt come incontact with the top of a rail car. As the clamp mechanism is lowered toa position equivalent to a minimum car height, the lock release rod 202contacts a stop or cam 204 which pivots the lock lever 186counterclockwise to disconnect the lock arm 190 from pin 196 in theexact sequence as described above, except that the lock lever isactuated by rod 202 rather than pin 184. As the cradle is returned tothe starting position (FIG. 14) with carriage 174 being raised upwardly,lock lever 186 drops to the position of FIG. 14 with the disengagementof rod 202 from stop 204 causing lock arm 190 to swing back intoengagement with stud 196.

A third embodiment of the present invention incorporates mechanism forrelief of the compressed truck springs of a rail car into a clampingmechanism 206 similar to that previously described. The clampingmechanism 206 of this embodiment includes a carriage having an uprightmember 208 engaged for movement relative to the cradle, an uppertransverse member 210 from which a clamp beam 212 is suspended, a liftbeam having a roller at its outer end in contact with a lift post andhaving a lock mechanism which engages a clamp member, and a mechanism214 for relieving the force of compression of rail car truck springs onthe clamping mechanism. The lift beam, lift post, and lock mechanism ofthis embodiment are identical to the lift beam and lock mechanismdescribed in the first embodiment and are not shown in the illustrationsof this embodiment.

The clamp beam 212 of this embodiment is suspended on shaft 216 betweenspaced, parallel arms 2100 of the transverse member 210. Spring yoke 218is situated at the central portion of the clamp beam 212 with a lowersection of the yoke 218 depending into a trapezoid-shaped slot in thebeam 212 (FIG. 18). Shaft 216 extends through yoke 218, throughvertically slotted holes 212a (FIGS. 20 and 21) in the parallel sides ofclampbeam 212, and is anchored at its ends to the parallel arms 210a oftransverse member 210 by keys 220. A pair of spherical-shapedelastomeric springs or resilient elements 222 are secured as by boltingbetween horizontal plates 224 of spring yoke 218 and plates 226 on theupper surface of the clamp beam 212.

To illustrate the problem of truck spring compression on the beamclamps, consider the dumping operation of a car R which weighs 60 tonsunloaded and which carries a 60 ton load. As the car is rotated to thedumping position and the ton load is dumped, the truck springs on thecar will transfer a force equal to the 60 ton load to the beam clampseven though the load has been dumped. This situation occurs because thesprings were compressed by the load as the clamps were lowered. Thesprings exert an upward force which neutralizes the downward forceexerted by the upright, loaded car, but, as the car is rotated, theforce of the springs, as well as the load in the car and the weight ofthe car itself, are shifted to the clamps. If the load dumps properly, aton load will be exerted on the clamps (the weight of the car plus theforce created by the springs). However, if the load should stick to thecar an extra 60 ton load will be placed on the clamps giving acumulative ton load on the clamps. The object, then, of this embodimentof the invention is to relieve the load on the clamps that is created byspring compression.

In operation, a loaded railroad car R is placed in the car dumper and amotor is energized to rotate the dumper to the dumping position.Clamping mechanism 206 lowers by gravity with the rotation of the dumperuntil clamp 212 contacts the top of car R. At this point, the clamplowering stops because shaft 216 is already at the top of slots 212a inclamp beam 212. As rotation continues to the 35 point, the clampmechanism locks the clamp beam in position. As the car is rotated fromits initial position to the dumping position, the weight of the car, itsload, and the force of the compressed springs transfer to the clampbeam. When this occurs the spherical-shaped, elastomeric springs 222 arecompressed or flattened to absorb the force of the compressed trucksprings as clamp beam 212 is pushed in a direction away from the top ofcar R by the force from the truck springs. The clamp beam 212 movesrelative to the upper transverse member 210 and shaft 216. consequently,the compressed railroad car truck springs extend to maintain the car incontact with the clamp beam. The force exerted on the clamp beam 212 bythe compressed truck springs is thus alleviated with the extension ofthe truck springs and the transfer of the spring compression to theelastomeric springs 222.

Although the best mode contemplated for carrying out the presentinvention has been herein shown and described, it will be apparent thatmodification and variation may be made without departing from what isregarded to be the subject matter of the invention.

What is claimed is:

1. In a rotary car dumper having a rotatable cradle to support a car andhaving a drive system for rotation of the cradle between a startingupright position and a dump position, the improvement comprising incombination, a car securing member in the cradle movable relative to thecradle and into contact with the car, a clamp mechanism comprising twosets of interdigitated plates, one of said sets carried by the cradleand the other set carried by the car securing member, a clampingmechanism operable when actuated to clamp the interdigitated platestogether to clamp the car securing member in the cradle, meansresponsive to the angular position of the cradle to actuate saidclamping mechanism, and means in said clamping mechanism to hold saidinterdigitated plates together with a predetermined force of a magnitudeindependent of the angular position of the cradle.

2. In a rotary car dumper having a rotatable cradle to support a car andhaving a drive system for rotation of the cradle between a startingupright position and a dump position, the improvement comprising incombination, a car securing member in the cradle movable relative to thecradle and into contact with the car, a clamp mechanism comprising twosets of interdigitated plates, one of said sets carried by the cradleand the other set carried by the car securing member, toggle membershaving a common joint mounted adjacent said interdigitated plates tolock said plates together on actuation of the toggle members, a leverhaving a counterweight, and means connecting said counterweighted leverto said common joint for actuation of the toggle members when the cradlehas rotated a predetermined car, a clamp mechanism comprising two setsof interdigitated plates, one of said sets mounted on the cradle and theother of said sets mounted on said carriage, a pressure member mountedon the carriage adjacent said interdigitated plates, toggle membersmounted on said carriage and having a common joint, one of said togglemembers engaging said pressure member for forceful movement thereof andclamping of said interdigitated plates on movement of said common joint,a lever pivotally mounted on said carriage, means connecting one end ofsaid lever to said common joint, and a counterweight on the opposite endof said lever to move said common joint in one direction or the other toclamp or release the car securing member to the cradle in response tothe rotational position of the cradle.

4. The mechanism of claim 3 including a stationary lift member mountedadjacent the cradle for engagement with said carriage when the cradle isin said starting upright position to hold said car securing member onthe carriage above the top of the car, said carriage lowering to lowerthe car securing member into engagement with the top of the car as thecradle turns away from said stationary member during rotation to saiddump position, said lever moving to a clamping position after apredetermined rotation of the cradle toward said dumping position;

@73 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,719,292 Dated March 6, 1973 Inventor(s) RALPH C. OUSKA It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1, line 66 delete "to" v Column 4, line 8, i delete "8cO205"Column 5, line 3, change "86a" to -86b-. Column 7, line 2, change 'll)"to lever--.

Column 7, line 23, delete "turns" Column 9, line "16, change "through"to -though-.

Signed and sealed this 3rd day of December 1974.

(SEAL) Attest: I

McCOY M. GIBSON JR. c. MARSHALL DANN Attesting Officer Conmiesioner ofPatents

1. In a rotary car dumper having a rotatable cradle to support a car andhaving a drive system for rotation of the cradle between a startingupright position and a dump position, the improvement comprising incombination, a car securing member in the cradle movable relative to thecradle and into contact with the car, a clamp mechanism comprising twosets of interdigitated plates, one of said sets carried by the cradleand the other set carried by the car securing member, a clampingmechanism operable when actuated to clamp the interdigitated platestogether to clamp the car securing member in the cradle, meansresponsive to the angular position of the cradle to actuate saidclamping mechanism, and means in said clamping mechanism to hold saidinterdigitated plates together with a predetermined force of a magnitudeindependent of the angular position of the cradle.
 1. In a rotary cardumper having a rotatable cradle to support a car and having a drivesystem for rotation of the cradle between a starting upright positionand a dump position, the improvement comprising in combination, a carsecuring member in the cradle movable relative to the cradle and intocontact with the car, a clamp mechanism comprising two sets ofinterdigitated plates, one of said sets carried by the cradle and theother set carried by the car securing member, a clamping mechanismoperable when actuated to clamp the interdigitated plates together toclamp the car securing member in the cradle, means responsive to theangular position of the cradle to actuate said clamping mechanism, andmeans in said clamping mechanism to hold said interdigitated platestogether with a predetermined force of a magnitude independent of theangular position of the cradle.
 2. In a rotary car dumper having arotatable cradle to support a car and having a drive system for rotationof the cradle between a starting upright position and a dump position,the improvement comprising in combination, a car securing member in thecradle movable relative to the cradle and into contact with the car, aclamp mechanism comprising two sets of interdigitated plates, one ofsaid sets carried by the cradle and the other set carried by the carsecuring member, toggle members having a common joint mounted adjacentsaid interdigitated plates to lock said plates together on actuation ofthe toggle members, a lever having a counterweight, and means connectingsaid counterweighted lever to said common joint for actuation of thetoggle members when the cradle has rotated a predetermined amount.
 3. Ina rotary car dumper having a rotatable cradle to support a car andhaving a drive system for rotation of the cradle between a startingupright position and a dump position, the improvement comprising incombination, a carriage movably mounted in the cradle, a car securingmember on the carriage for movement with the carriage into and out ofengagement with the car, a clamp mechanism comprising two sets ofinterdigitated plates, one of said sets mounted on the cradle and theother of said sets mounted on said carriage, a pressure member mountedon the carriage adjacent said interdigitated plates, toggle membersmounted on said carriage and having a common joint, one of said togglemembers engaging said pressure member for forceful movement thereof andclamping of said interdigitated plates on movement of said common joint,a lever pivotally mounted on said carriagE, means connecting one end ofsaid lever to said common joint, and a counterweight on the opposite endof said lever to move said common joint in one direction or the other toclamp or release the car securing member to the cradle in response tothe rotational position of the cradle.